This section applies to all properties in the City that are not single-family properties subject to § 3-2{“Assessment of base fee – Single-family properties”} of this subtitle. The fee for properties subject to this section is the rate per Equivalent Residential Unit (or “ERU”) set in accordance with § 3-4 {“Initial rates”} or <cite data-path="|27|§3-5">§ 3-5 {“Subsequent rates”} of this subtitle</cite> times the number of ERUs on the property. For this purpose, 1 ERU comprises 1,050 square feet of impervious surface area. For properties subject to this section, the following methods may be used, at the sole discretion of the Director of Public Works, to determine the impervious surface measurement of a property:geographic information systems analysis of aerial photographs; measurement from approved as-built engineering drawings that are signed and sealed by a professional engineer; field surveys that are signed and sealed by a professional engineer or professional land surveyor; and the use of any additional information that can reliably supplement the data derived from the other measures. The resultant ERU count shall be rounded to the nearest whole number. The computations and back-up materials for all resultant ERU counts shall be maintained by the Department of Public Works and made available to the public, in the Department’s main office and on the Department’s website. The minimum assessed stormwater fee for all properties subject to this section shall be equal to the fee for 1 ERU. The maximums set by paragraphs (2) and (3) of this subsection do not apply to any property or portion of a property for which a credit or exemption has been applied for under <cite data-path="|27|§3-6">§ 3-6 {“Credits; Exemptions”} of this article</cite>. Subject to subparagraph (ii) of this paragraph, the fee for any property that is subject to property tax and is subject to assessment under this section may not exceed an amount equal to 20% of the total of all State and local real property taxes levied on the property. This paragraph (2) applies only to properties for which each of the following exceeds $1,000:the net State and local real property taxes levied on the property; and the storm water remediation fee otherwise assessable under <cite data-path="|27">this article</cite>. Notwithstanding § 3-4 {“Initial rates”} and § 3-5 {“Subsequent rates”}, the fee for structures located on property owned by religious groups or organizations is $12 per ERU per year if:the property is not subject to State or City property tax; and the structures on the property are used exclusively for:places of worship; or elementary, middle, or high school education. Ord. 13-143